Point machine for movable frogs

ABSTRACT

In a switch actuator for movable frogs ( 1 ), comprising at least one cylinder piston unit ( 5 ) having a defined preset piston stroke, the cylinder piston unit ( 5 ) is connected with bearings ( 6 ) capable of being displaced in the axial direction of the piston stroke, which bearings are connected with a stationary substructure for the adjustment of a defined center position of the piston stroke and the driver for the movable frog ( 1 ). The driver for the movable frog ( 1 ) is coupled with the cylinder piston unit ( 5 ) with first stops ( 9 ) displaceable in the axial direction being interposed.

The invention relates to a switch actuator for movable frogs, comprisingat least one cylinder piston unit having a defined preset piston stroke.

With switch actuators for movable frogs it is necessary to adapt theactuating device, and switch actuator, to the exact displacement path ofthe movable frog. The two positions, or end positions, in thedisplacement of a frog must each ensure precise abutment on the wingrail, and displacement must naturally occur in a manner so as to avoidoverstressing of the switch actuator in any of these abutment positions.Due to manufacturing tolerances as well as frog and wing rail wear, itmust be feasible to adjust the stroke of the actuating system to theexact displacement path actually required of the frog between theright-hand and left-hand abutment positions. Such a correct adjustmentof the stroke must also be feasible on site in the laid switch.

Especially when using trough sleepers, and with an increasing extent ofprefabrication of hydraulic switch actuators, cylinder piston units arealready at the factory being provided with preset cylinder strokes, thuscalling for a precise adjustment in the trough sleeper as well as thesetting of the actually required displacement path subsequently.

The invention aims to provide a switch actuator of the initially definedkind, which enables the use of prefabricated cylinder piston unitshaving defined preset piston strokes, wherein the precise adjustment ofthe actually required displacement path will still be safeguardedsubsequently upon installation into the laid switch. To solve thisobject, the configuration of the switch actuator of the initiallydefined kind according to the invention essentially consists in that thecylinder piston unit is connected with bearings capable of beingdisplaced in the axial direction of the piston stroke, which bearingsare connected with a stationary substructure for the adjustment of adefined center position of the piston stroke and the driver for themovable frog, and that the driver for the movable frog is coupled withthe cylinder piston unit with stops displaceable in the axial directionbeing interposed. Due to the fact that the cylinder piston unit isconnected with bearings capable of being displaced in the direction ofthe piston, is has become feasible to arrange in a sleeper, particularlyin a trough sleeper, a cylinder piston unit designed with a definedpiston stroke at the factory, whose stroke preset at the factory must inany event be larger than the actual stroke of the movable switch part orfrog, in a manner so as to enable a precise positioning in the sense ofa defined center position of the displacement path of the cylinderpiston unit. To this end, the displaceable bearings must beappropriately displaced such that the cylinder piston unit is altogetheroriented in a manner that the center position of the movable frog point,or movable frog, corresponds with the center position of the presetstroke of the cylinder piston unit. Departing from such a basic centerposition adjustment, it has now become feasible, by the driver for themovable frog being coupled with the cylinder piston unit with stopsdisplaceable in the axial direction being interposed, to shift thesedisplaceable stops to such an extent that the driver will each becoupled with the cylinder piston unit, and hence define the displacementmovement of the frog, only after an accordingly adjusted idle stroke.The extent by which the preset piston stroke of the cylinder piston unitis larger than the displacement path of the movable frog actuallyrequired in the installed position is compensated by the adjustment ofthe respective idle stroke such that, in the main, a displacement of themovable frog between the two abutment positions is feasible by theexactly required extent and at an accordingly extremely small toleranceof about 0.1 mm.

In order to ensure such highly precise setting without entailing therisk of any premature wear of the actuating members, the driver or thecylinder piston units, the configuration is advantageously devised suchthat the driver comprises a sliding block and enables a relativemovement of the frog along two mutually crossing axes different from theaxis of the displacement stroke. Such a quasi-cardanic suspension allowsfor the appropriate absorption of relative movements of switch partsunder the rolling load without overstressing the high-precision-orienteddrivers and stops as well as the coupling parts to the cylinder pistonunit.

The exact setting of the stroke, or exact setting of the idle stroke, isfeasible in a simple manner in that the driver, in the direction of thedisplacement stroke, is traversed by a spindle having different threaddirections on the two sides of the driver, and cooperates with nutsguided in a rotationally fast manner to adjust the idle strokes. Since,as mentioned in the beginning, the cylinder piston unit initially isprecisely adjusted to its center position, such a spindle at the sametime enables the displacement stroke to be altered on both sides of thecenter, and hence altogether adjusted to the exactly requireddisplacement path of the frog, with identical idle strokes being formedon either side of the center position.

The movable frog during its pivotal movement, to be precise, is guidedand moved over a circular arc, especially near the frog point, so that,due to the linear orientation of the displacement stroke, a number ofadditional forces and, in particular, pivot forces have to be taken upwithout entailing any risk of overstressing. The appropriate resiliencein the longitudinal direction of the rails will be safeguarded in asimple manner by conventional means such as, for instance, oblong holesor the like. However, in order to ensure a relative pivotal movement ofthe frog and, in particular, frog point relative to the driver and, inparticular, sliding block of the driver, and avoid the absorption ofvertical movements during the passage of a switch under rolling load, orat a shift of the frog point in cooperation with a rolling device, theconfiguration is advantageously devised such that the driver is arrangedto be pivotable about the axis of the cylinder piston unit, and that thesliding block of the driver carries or comprises a tappet or cylinderportion arranged to be pivotable about an axis extending substantiallynormal to the direction of the displacement stroke.

As in correspondence with a further development, an adjustment deviceparticularly simple in terms of construction and readily actuatable evenfrom outside, for adjusting the center position of the cylinder pistonunit in a trough sleeper is devised such that the bearings capable ofbeing displaced in the axial direction of the piston stroke are eachdesigned as a fork head whose fork is supported in a rotationally fastmanner while displaceable in the axial direction and connected with thehydraulic cylinder piston unit via a bearing journal, and that to thefork head is connected a fork head screw that traverses a stop andcarries an adjusting nut, turning of which causes an axial displacementof the fork head. Relative displacement relative to the outer side ofthe trough sleeper may be obtained via the fork head screw by anappropriate turn of the adjusting screw, the respective adjustment beingobtained by the actuation of adjusting nuts on both sides of the troughsleeper. In order to enable the particularly simple insertion of aprefabricated and preset cylinder piston unit into such a trough sleeperwhile, at the same time, safeguarding that the respective anti-rotationlocks will enter into effect after insertion, which is necessary for anaxial displacement and hence the exact positioning of the center stroke,the configuration is advantageously devised such that the stop isdesigned as an upwardly open slot of a wall of a trough sleeperextending transversely to the longitudinal direction of the sleeper, orof a stationary part of a switch.

In the main, there is thus provided an adjustment locking cylinderfulfilling the functions of displacing, locking, and monitoring thelocking of, a movable switch part and having a configuration set at adefined stroke at the factory, said stroke set at the factory being inany event larger than the stroke of the movable switch part. The actualadaptation of the stroke to a particular rail switch is performed byadjusting the idle stroke between the driver on the switch lockingcylinder and the movable switch part, the stroke of the switch partbeing variable, and hence continuously adaptable, by regulating the idlestroke at a constant cylinder stroke. On the left-handed andright-handed thread, respectively, in the center region of thesymmetrical spindle rod of the spindle drive, are each provided twodriver nuts guided positively, yet slidingly on the driver housing,while the spindle rod itself passes through a sliding block. In order toensure an accordingly attenuated impact after having passed the idlestroke, the nuts may each cooperate with the sliding block or slidingblock carrier of the driver part via an interposed cup spring, whereinthe sliding block itself cooperates with the structural componentsdirectly connected with the movable frog. The sliding block, whichitself forms part of the driver, thus takes up those structuralcomponents which are to ensure the transmission of the displacement pathonto the frog, these parts immersing in the sliding block, in turn,pivotally engaging in the sliding block to prevent respectiveoverstressing.

The entire locking device is mounted to frame parts of a trough sleeper,whereby the fork heads, which are each provided with a spindle,cooperate with mating adjusting nuts in order to enable the adjustmentof the center position. The steps required for precision-setting, thus,consist in initially adjusting to the maximum stroke the idle stroke onone side, displacing the frog into an end position, measuring thedistance between frog and wing rail, and displacing the frog into theother end position while measuring the distance anew, whereupon centeradjustment is carried out until the same distance between frog and wingrail is reached on both sides. Departing from this center adjustment theidle stroke is then reduced by the distance measure, which finallyresults in the exact adjustment.

In the following, the invention will be explained in more detail by wayof an exemplary embodiment schematically illustrated in the drawing.Therein,

FIG. 1 shows a vertical section through a switch including a switchactuator;

FIG. 2 is a detailed view of the switch actuator and driver for themovable frog;

FIG. 3 is a section along line III—III of FIG. 1; and

FIG. 4 is a detailed view of the displaceable bearings used to mount thecylinder piston unit in the trough sleeper.

In FIG. 1, a movable frog denoted by 1 is displaceable into abutment onthe wing rail 2 or 3, respectively. All of the components of theswitching, locking and checking devices are arranged in a trough sleeper4 below the track plane. The switching device 5 in this case iscomprised of a cylinder piston unit and articulately connected to thestationary trough sleeper via bearings 6. As will be explained below,the bearings 6 are devised such that an adjustment of the switchingdevice 5 is feasible in the longitudinal direction of the sleeper in thesense of double arrow 7 so as to enable the adjustment of the centerposition of the cylinder piston unit. The switching device 5 is coupledto a driver part 8 which transmits the switching movement to the movablefrog 1. Driving is effected via first displaceable stops 9 cooperatingwith a sliding block 10, which in turn is connected with the base plate11 of the movable frog 1. The precise adjustment of the effective strokeof the movable frog 1 is feasible by the adjustment of an idle strokebetween these first stops 9 and the sliding block 10.

FIG. 2 depicts the individual coupling and driver parts on an enlargedscale. It is apparent that the driver 8, which is pivotally supported onthe cylinder piston unit, is comprised of two sleeves 34 surrounding thecylinder piston unit 5 and having projections 12 through which a spindle13 passes, the position of the spindle 13 relative to the projections 12of the driver 8 being fixed by stop shoulders formed by the largerdiameter-region 14 of the spindle 13. The larger-diameter-region 14 ofthe spindle 13 further comprises two threaded portions 15 and 16 havingmutually opposed thread directions. A turn of the spindle causes thefirst stop parts 9 mounted on the threaded regions 15 and 16 in arotationally fast manner to be moved away from each other, or towardseach other, in the manner of a driver nut in the sense of double arrow17. The driver part further comprises a sliding block 10 through whichthe spindle 13 passes and on which it is mounted so as to be slidinglymovable between the first stops 9. By displacing the first stops 9 inthe sense of double arrow 17, it is feasible to adjust the idle stroke abetween the first stops 9 and the sliding block 10 in order to reducethe switching stroke of the cylinder piston unit 5 to the respectivelyrequired displacement stroke of the movable frog 1.

The sliding block 10 further comprises an inner part 18 including acylinder portion with a cylinder axis 19 so as to allow for a pivotalmovement of the cylinder part 18 about the rotational axis 19 relativeto the outer part 20 of the sliding block 10 and hence relative to thedriver 8. The cylinder part 18 engages in a driver stirrup 21, which inturn is welded with the base plate 11 of the movable frog 1, so that, inthe main, a compensation movement is rendered feasible during thepivotal movement of the frog 1 relative to the switching device 5, whichis necessary for the switching movement of the frog 1.

From the side view according to FIG. 3, the stirrup-shaped form of thedriver part 21 is apparent, it being recognizable that the sliding block10 is slidingly movable in the stirrup-shaped driver part 21 alongdouble arrow 22 such that longitudinal displacements of the movable frog1 possibly caused, for instance, by thermal expansions will not betransmitted to the switching mechanism. Furthermore, it is apparent thatthe first stops 9, i.e. the driver nuts, are supported on the sleeves 34of the drivers in a rotationally fast manner. This is to obtain ananti-rotation lock of the first stops 9 relative to the rotation of thespindle and to ensure the axial displacement of the first stops 9. Thepositioning of the driver 8 relative to the axis 23 at a central angle αoccurs as a function of the upward or downward movement in the sense ofdouble arrow 24 and the displacement in the longitudinal direction ofthe rail in the sense of double arrow 22, of the movable frog such thatforces resulting from these movements will be prevented from beingintroduced into the cylinder piston unit.

FIG. 4 elucidates the mounting of the cylinder piston unit 5 on thetrough sleeper 4. In this case, the bearing 6 is provided with a forkhead 25 whose fork is supported in a rotationally fast manner whilebeing displaceable in the direction of the axis 23 of the cylinderpiston unit 5, and is connected with the hydraulic cylinder piston unit5 via a bearing journal 26. Here, the fixation of the rotary position ofthe fork head 25 is effected in that the fork head 25 is supported on aweb 27 departing from the side wall of the trough sleeper. The fork head25 is connected with a fork head screw 28 carrying an adjusting nut 29.A turn of the adjusting nut 29, whose axial position is fixed by the aidof the second stop 30 rigidly connected with the trough sleeper 4,causes an axial displacement of the fork head 25 in the sense of doublearrow 31. The adjusted axial position of the fork head is fixed by theaid of union part 32 and nut 33. This axial displacement of the forkhead, and hence the cylinder piston unit, which must, of course, takeplace in both of the adjustable bearings 6 on both sides of the cylinderpiston unit, enables the precise adjustment of the center position ofthe piston stroke.

1. A switch actuator for movable frogs, comprising at least one cylinderpiston unit having a defined preset piston stroke, wherein the cylinderpiston unit (5) is connected with bearings (6) capable of beingdisplaced relative to said cylinder piston unit (5) in an axialdirection (31) of the piston stroke, said bearings are connected to astationary substructure by an adjusting means for adjusting a definedcenter position of the piston stroke and a driver for a movable frog(1), and the driver for the movable frog (1) is coupled with thecylinder piston unit with first stops (9) being interposed between thecylinder piston unit (5) and the movable frog (1), said first stopsbeing displaceable in the axial direction of the piston stroke.
 2. Aswitch actuator according to claim 1, wherein the driver comprises asliding block (10) and enables a relative movement of the frog (1) alongtwo mutually crossing directions different from a direction of adisplacement stroke.
 3. A switch actuator according to claim 1, whereinthe driver, in a direction of a displacement stroke, is traversed by aspindle (13) having different thread directions on two sides of thedriver, and cooperates with said first stops (9) guided in arotationally fast manner to adjust idle strokes.
 4. A switch actuatoraccording to claim 1, wherein the driver is arranged to be pivotableabout an axis of the cylinder piston unit (5), and further comprising asliding block (10) of the driver comprising a tappet or cylinder portion(18) arranged to be pivotable about an axis (19) extending substantiallynormal to a direction of a displacement stroke.
 5. A switch actuatoraccording to claim 1, wherein the bearings (6) capable of beingdisplaced in the axial direction (31) of the piston stroke are eachdesigned as a fork head (25) whose fork is supported in a rotationallyfast manner while displaceable in the axial direction (31) and connectedwith the hydraulic cylinder piston unit (5) via a bearing journal (26),and the fork head (25) is connected to a fork head screw (28) thattraverses a second stop (30) and comprises an adjusting nut (29),turning of which causes an axial displacement of the fork head (25). 6.A switch actuator according to claim 5, wherein the second stop (30) isdesigned as an open slot of a wall of a trough sleeper (4) extendingtransversely to a longitudinal direction of the sleeper, or of astationary switch part.
 7. A switch actuator according to claim 2,wherein the driver, in the direction of the displacement stroke, istraversed by a spindle (13) having different thread directions on twosides of the driver, and cooperates with said first stops (9) guided ina rotationally fast manner to adjust idle strokes.
 8. A switch actuatoraccording to claim 2, wherein the driver is arranged to be pivotableabout an axis of the cylinder piston unit (5), and the sliding block(10) of the driver comprises a tappet or cylinder portion (18) arrangedto be pivotable about an axis (19) extending substantially normal to thedirection of the displacement stroke.
 9. A switch actuator according toclaim 3, wherein the driver is arranged to be pivotable about an axis ofthe cylinder piston unit (5), and further comprising a sliding block(10) of the driver comprising a tappet or cylinder portion (18) arrangedto be pivotable about an axis (19) extending substantially normal to thedirection of the displacement stroke.
 10. A switch actuator according toclaim 7, wherein the driver is arranged to be pivotable about an axis ofthe cylinder piston unit (5), and the sliding block (10) of the drivercomprises a tappet or cylinder portion (18) arranged to be pivotableabout an axis (19) extending substantially normal to the direction ofthe displacement stroke.
 11. A switch actuator according to claim 2,wherein the bearings (6) capable of being displaced in the axialdirection (31) of the piston stroke are each designed as a fork head(25) whose fork is supported in a rotationally fast manner whiledisplaceable in the axial direction (31) and connected with thehydraulic cylinder piston unit (5) via a bearing journal (26), and thefork head (25) is connected to a fork head screw (28) that traverses asecond stop (30) and comprises an adjusting nut (29), turning of whichcauses an axial displacement of the fork head (25).
 12. A switchactuator according to claim 3, wherein the bearings (6) capable of beingdisplaced in the axial direction (31) of the piston stroke are eachdesigned as a fork head (25) whose fork is supported in a rotationallyfast manner while displaceable in the axial direction (31) and connectedwith the hydraulic cylinder piston unit (5) via a bearing journal (26),and the fork head (25) is connected to a fork head screw (28) thattraverses a second stop (30) and comprises an adjusting nut (29),turning of which causes an axial displacement of the fork head (25). 13.A switch actuator according to claim 4, wherein the bearings (6) capableof being displaced in the axial direction (31) of the piston stroke areeach designed as a fork head (25) whose fork is supported in arotationally fast manner while displaceable in the axial direction (31)and connected with the hydraulic cylinder piston unit (5) via a bearingjournal (26), and the fork head (25) is connected to a fork head screw(28) that traverses a second stop (30) and comprises an adjusting nut(29), turning of which causes an axial displacement of the fork head(25).
 14. A switch actuator according to claim 7, wherein the bearings(6) capable of being displaced in the axial direction (31) of the pistonstroke are each designed as a fork head (25) whose fork is supported ina rotationally fast manner while displaceable in the axial direction(31) and connected with the hydraulic cylinder piston unit (5) via abearing journal (26), and the fork head (25) is connected to a fork headscrew (28) that traverses a second stop (30) and comprises an adjustingnut (29), turning of which causes an axial displacement of the fork head(25).
 15. A switch actuator according to claim 8, wherein the bearings(6) capable of being displaced in the axial direction (31) of the pistonstroke are each designed as a fork head (25) whose fork is supported ina rotationally fast manner while displaceable in the axial direction(31) and connected with the hydraulic cylinder piston unit (5) via abearing journal (26), and the fork head (25) is connected to a fork headscrew (28) that traverses a second stop (30) and comprises an adjustingnut (29), turning of which causes an axial displacement of the fork head(25).
 16. A switch actuator according to claim 9, wherein the bearings(6) capable of being displaced in the axial direction (31) of the pistonstroke are each designed as a fork head (25) whose fork is supported ina rotationally fast manner while displaceable in the axial direction(31) and connected with the hydraulic cylinder piston unit (5) via abearing journal (26), and the fork head (25) is connected to a fork headscrew (28) that traverses a second stop (30) and comprises an adjustingnut (29), turning of which causes an axial displacement of the fork head(25).
 17. A switch actuator according to claim 10, wherein the bearings(6) capable of being displaced in the axial direction (31) of the pistonstroke are each designed as a fork head (25) whose fork is supported ina rotationally fast manner while displaceable in the axial direction(31) and connected with the hydraulic cylinder piston unit (5) via abearing journal (26), and the fork head (25) is connected to a fork headscrew (28) that traverses a second stop (30) and comprises an adjustingnut (29), turning of which causes an axial displacement of the fork head(25).
 18. A switch actuator according to claim 11, wherein the secondstop (30) is designed as an open slot of a wall of a trough sleeper (4)extending transversely to a longitudinal direction of the sleeper, or ofa stationary switch part.
 19. A switch actuator according to claim 12,wherein the second stop (30) is designed as an open slot of a wall of atrough sleeper (4) extending transversely to a longitudinal direction ofthe sleeper, or of a stationary switch part.
 20. A switch actuatoraccording to claim 13, wherein the second stop (30) is designed as anopen slot of a wall of a trough sleeper (4) extending transversely to alongitudinal direction of the sleeper, or of a stationary switch part.